Duncan was speaking in San Francisco, Calif., at AERA’s annual five-day conference. His remarks came on the same day that both Dennis Van Roekel, president of the National Education Association, and Randi Weingarten, president of the American Federation of Teachers, proposed a moratorium for negative consequences on teacher evaluations tied to the first few years of implementing Common Core State Standards, a more in-depth set of math and reading benchmarks for standardized tests.

Duncan also addressed the difficulties schools may face during the first few years of Common Core implementation. When asked if he would put a moratorium on standardized testing while schools got adjusted to Common Core Standards, he said, “We understand this is a difficult tough time of transition. We’re spending a huge amount of time listening to ideas about how to do it."